Messages in this thread Patch in this message | | | From | Joel Savitz <> | Subject | [RFC PATCH 3/3] drivers/mfd: rpisense: Raspberry Pi senseHAT 8x8 LED matrix display driver | Date | Fri, 6 Aug 2021 20:27:22 -0400 |
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This patch implements control of the 8x8 RGB LED matrix display.
Signed-off-by: Charles Mirabile <cmirabil@redhat.com> Signed-off-by: Mwesigwa Guma <mguma@redhat.com> Signed-off-by: Joel Savitz <jsavitz@redhat.com> --- drivers/mfd/Makefile | 1 + drivers/mfd/rpisense-display.c | 242 +++++++++++++++++++++++++++++++++ 2 files changed, 243 insertions(+) create mode 100644 drivers/mfd/rpisense-display.c
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 71356153ccdc..974518d9801b 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -265,6 +265,7 @@ obj-$(CONFIG_MFD_STMFX) += stmfx.o obj-$(CONFIG_MFD_KHADAS_MCU) += khadas-mcu.o obj-$(CONFIG_MFD_RPISENSE) += rpisense-core.o obj-$(CONFIG_MFD_RPISENSE) += rpisense-js.o +obj-$(CONFIG_MFD_RPISENSE) += rpisense-display.o obj-$(CONFIG_MFD_ACER_A500_EC) += acer-ec-a500.o obj-$(CONFIG_MFD_QCOM_PM8008) += qcom-pm8008.o diff --git a/drivers/mfd/rpisense-display.c b/drivers/mfd/rpisense-display.c new file mode 100644 index 000000000000..10a34fa0eece --- /dev/null +++ b/drivers/mfd/rpisense-display.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Raspberry Pi Sense HAT 8x8 LED matrix display driver + * http://raspberrypi.org + * + * Copyright (C) 2015 Raspberry Pi + * Copyright (C) 2021 Charles Mirabile, Mwesigwa Guma, Joel Savitz + * + * Original Author: Serge Schneider + * Revised for upstream Linux by: Charles Mirabile, Mwesigwa Guma, Joel Savitz + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/mod_devicetable.h> + +#include <linux/mfd/rpisense.h> + +#define GAMMA_SIZE sizeof_field(struct rpisense_display, gamma) +#define VMEM_SIZE sizeof_field(struct rpisense_display, vmem) + +static bool lowlight; +module_param(lowlight, bool, 0); +MODULE_PARM_DESC(lowlight, "Reduce LED matrix brightness to one third"); + +static const u8 gamma_presets[][GAMMA_SIZE] = { + [GAMMA_DEFAULT] = { + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, + 0x02, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0E, 0x0F, 0x11, + 0x12, 0x14, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F, + }, + [GAMMA_LOWLIGHT] = { + 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, + 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, + 0x03, 0x03, 0x03, 0x04, 0x04, 0x05, 0x05, 0x06, + 0x06, 0x07, 0x07, 0x08, 0x08, 0x09, 0x0A, 0x0A, + }, +}; + +static const struct file_operations rpisense_display_fops; + +static int rpisense_display_probe(struct platform_device *pdev) +{ + int ret; + + struct rpisense *rpisense = dev_get_drvdata(&pdev->dev); + struct rpisense_display *rpisense_display = &rpisense->display; + + memcpy(rpisense_display->gamma, gamma_presets[lowlight], GAMMA_SIZE); + + memset(rpisense_display->vmem, 0, VMEM_SIZE); + + mutex_init(&rpisense_display->rw_mtx); + + rpisense_display->mdev = (struct miscdevice) { + .minor = MISC_DYNAMIC_MINOR, + .name = "sense-hat", + .mode = 0666, + .fops = &rpisense_display_fops, + }; + + ret = misc_register(&rpisense_display->mdev); + if (ret < 0) { + dev_err(&pdev->dev, "Could not register 8x8 LED matrix display.\n"); + return ret; + } + + dev_info(&pdev->dev, "8x8 LED matrix display registered with minor number %i", + rpisense_display->mdev.minor); + + rpisense_update_display(rpisense); + return 0; +} + +static int rpisense_display_remove(struct platform_device *pdev) +{ + struct rpisense *rpisense = dev_get_drvdata(&pdev->dev); + struct rpisense_display *rpisense_display = &rpisense->display; + + misc_deregister(&rpisense_display->mdev); + return 0; +} + +static loff_t rpisense_display_llseek(struct file *filp, loff_t pos, int whence) +{ + loff_t base; + + switch (whence) { + case SEEK_SET: + base = 0; + break; + case SEEK_CUR: + base = filp->f_pos; + break; + case SEEK_END: + base = VMEM_SIZE; + break; + default: + return -EINVAL; + } + base += pos; + if (base < 0 || base >= VMEM_SIZE) + return -EINVAL; + filp->f_pos = base; + return base; +} + +static ssize_t +rpisense_display_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) +{ + struct rpisense *rpisense = container_of(filp->private_data, struct rpisense, display.mdev); + struct rpisense_display *rpisense_display = &rpisense->display; + ssize_t retval = -EFAULT; + + if (*f_pos >= VMEM_SIZE) + return 0; + if (*f_pos + count > VMEM_SIZE) + count = VMEM_SIZE - *f_pos; + if (mutex_lock_interruptible(&rpisense_display->rw_mtx)) + return -ERESTARTSYS; + if (copy_to_user(buf, rpisense_display->vmem + *f_pos, count)) + goto out; + *f_pos += count; + retval = count; +out: + mutex_unlock(&rpisense_display->rw_mtx); + return retval; +} + +static ssize_t +rpisense_display_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) +{ + struct rpisense *rpisense = container_of(filp->private_data, struct rpisense, display.mdev); + struct rpisense_display *rpisense_display = &rpisense->display; + u8 temp[VMEM_SIZE]; + + if (*f_pos >= VMEM_SIZE) + return -EFBIG; + if (*f_pos + count > VMEM_SIZE) + count = VMEM_SIZE - *f_pos; + if (copy_from_user(temp, buf, count)) + return -EFAULT; + if (mutex_lock_interruptible(&rpisense_display->rw_mtx)) + return -ERESTARTSYS; + memcpy(rpisense_display->vmem + *f_pos, temp, count); + rpisense_update_display(rpisense); + *f_pos += count; + mutex_unlock(&rpisense_display->rw_mtx); + return count; +} + +static long rpisense_display_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct rpisense *rpisense = container_of(filp->private_data, struct rpisense, display.mdev); + struct rpisense_display *rpisense_display = &rpisense->display; + void __user *user_ptr = (void __user *)arg; + u8 temp[GAMMA_SIZE]; + int ret; + + if (mutex_lock_interruptible(&rpisense_display->rw_mtx)) + return -ERESTARTSYS; + switch (cmd) { + case SENSEDISP_IOGET_GAMMA: + if (copy_to_user(user_ptr, rpisense_display->gamma, GAMMA_SIZE)) { + ret = -EFAULT; + goto out_unlock; + } + ret = 0; + goto out_unlock; + case SENSEDISP_IOSET_GAMMA: + if (copy_from_user(temp, user_ptr, GAMMA_SIZE)) { + ret = -EFAULT; + goto out_unlock; + } + ret = 0; + goto out_update; + case SENSEDISP_IORESET_GAMMA: + if (arg < GAMMA_DEFAULT || arg >= GAMMA_PRESET_COUNT) { + ret = -EINVAL; + goto out_unlock; + } + memcpy(temp, gamma_presets[arg], GAMMA_SIZE); + ret = 0; + goto out_update; + default: + ret = -EINVAL; + goto out_unlock; + } +out_update: + memcpy(rpisense_display->gamma, temp, GAMMA_SIZE); + rpisense_update_display(rpisense); +out_unlock: + mutex_unlock(&rpisense_display->rw_mtx); + return ret; +} + +static const struct file_operations rpisense_display_fops = { + .owner = THIS_MODULE, + .llseek = rpisense_display_llseek, + .read = rpisense_display_read, + .write = rpisense_display_write, + .unlocked_ioctl = rpisense_display_ioctl, +}; + +#ifdef CONFIG_OF +static const struct of_device_id rpisense_display_id[] = { + { .compatible = "rpi,rpi-sense-fb" }, + { }, +}; +MODULE_DEVICE_TABLE(of, rpisense_display_id); +#endif + +static struct platform_device_id rpisense_display_device_id[] = { + { .name = "rpi-sense-fb" }, + { }, +}; +MODULE_DEVICE_TABLE(platform, rpisense_display_device_id); + +static struct platform_driver rpisense_display_driver = { + .probe = rpisense_display_probe, + .remove = rpisense_display_remove, + .driver = { + .name = "rpi-sense-fb", + }, +}; + +module_platform_driver(rpisense_display_driver); + +MODULE_DESCRIPTION("Raspberry Pi Sense HAT 8x8 LED matrix display driver"); +MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>"); +MODULE_LICENSE("GPL"); + -- 2.27.0
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